One and Only
by CardyDesu
Summary: He did not know when his view of her began to change. The first and only demon Tomioka Giyuu did not kill. [One Shot] SPOILER for the manga, read at your own discretion. Romance, if you squint.


**Disclaimer**: I do not own _Kimetsu no Yaiba_.

* * *

He did not know when his view of her began to change.

The first and only demon Tomioka Giyuu did not kill.

In the beginning, she looked just like any bloodthirsty demon trying to devour the human boy beneath her. The oversized fangs probing out from her mouth and the slit, demonic eyes were a giveaway to her condition. It was another human-turned-demon, Giyuu remembered thinking, and her brother happened to be the unfortunate fool to be nearly eaten.

The boy still defended her with every fiber of his being. Even when the demon was within Giyuu's clutches, ready to be slaughtered. Even when the boy was heavily at a disadvantage; he still attacked after being harshly reprimanded by the _hashira_.

Giyuu was taken aback by the brother's ability, if only for a second, before his grasp on the demon loosened and she kicked him away. He had lamented over his carelessness, was ready to see the red of blood spill from the boy—but rather than devouring the human Giyuu had seen dozens of demons had done before, the girl-demon kneeled in front of her brother protectively.

Dried blood coated her forehead; it stained her pale pink _nagajuban_. Yet, she did not attack her brother at the earliest opportunity to recover. Instead, she was attacking _him_.

Demons were simple but dangerous creatures. They only cared about sustaining their life; protecting themselves and eating humans. And yet, this newly turned demon was acting out in rage against him, _protecting_ a human.

It was ludicrous.

Implausible.

But it was reality.

And in those brief moments of Giyuu sheathing his sword and merely dodging the demon's onslaught, he reached an undeniable conclusion. These pair of siblings was different.

"_It wasn't Nezuko! She'd never eat humans!"_

Countless times, Giyuu had seen others proclaimed that. And countless times, the demons would prove them wrong. There were lives the pillar was not able to save, always promising to do better—to be stronger—so the demons would never win.

But for once, in his nineteen years of life, he had never once seen a demon abandon a meal for _protection_.

Maybe it was mercy. Maybe it was only a whim. But Giyuu allowed that demon to live, creating a makeshift bamboo muzzle to tie around her fanged mouth and wrapped her back in the mauve kimono. And, with careful hands, he wiped the blood away from her face.

She looked peaceful asleep, more girl than demon without the blood soaking her forehead. Then, she was returned to her brother's collapsed form; both siblings fainted in the cold snow.

It had been two years. Two years since Giyuu sent the pair of siblings to his old mentor's residence. Urokodaki Sakonji would be perfect to train the boy, Tanjirou he later learned the name of, to become a demon slayer while simultaneously watching over the demon girl. He would have expected his mentor to be shocked, sparing a demon was a violation to the Demon Slaying Corps, but that demon was unique so he placed his trust in them.

For awhile, Giyuu never knew if the duo had made it to Urokodaki alive. But, a few times after the Water Pillar had met the Kamado siblings, he wondered if the demons he faced would show the same…_humanity_ as that girl.

They never did.

And so, they were slain.

The two of them had faded from his mind as he continued his duty of slaying demons. It was a repetitive cycle; his way of life. Demons were the enemy and he was devoted to killing them. But, at times, in the corner of his mind, he thought he would see long black hair with orange tint on the bottom—a girl—a demon—adding onto the list of ghosts haunting him.

Maybe, he had made a mistake.

So, when the letter from Urokodaki reached him, Giyuu was more than surprised that—the siblings he spared were still alive. The demon had fallen into a coma, the original bamboo muzzle never removed, and the brother was working hard to become a demon slayer. His former teacher had praised the two in his own subtle way. Based on Urokodaki's brief message, Giyuu realized the old man to have hope for these two as well.

Tanjirou and Nezuko were an anomaly to their cycle of demon slaying. The appearance of them had shifted something in their world of demons and death. What it was, Giyuu did not know at that time.

But, with Urokodaki's approval, a letter was written to Oyakata-sama regarding Giyuu's action of sparing the demon and her unique conditions. Urokodaki had guessed Nezuko's long period of sleep was due to her substitute for flesh sustainability and he had been quietly conditioning the girl to protect humans. Should she ever harm a human, the three, Kamado Tanjirou, Urokodaki Sakonji, and Tomioka Giyuu would commit _seppuku_.

Giyuu had never thought he would place his life in a demon's hands before. There was always the risk of death when fighting against the bloodthirsty creatures but—never had he thought one day, his life rested on the one made to kill him.

It was a feeling of hopeless hope. They may be the key to ending this bloodshed nightmare. If there was ever a chance in defeating Kibutsuji Muzan, it would be them.

Giyuu never said those thoughts out loud. His actions had already spoken for him.

In the darkness of the night in Natagumo Mountain, Tomioka Giyuu reunited with the Kamado siblings.

At first, he did not recognize him. The brazen child dared to preach about demons having human emotions when their job as the Demon Slaying Corps was to eradicate them. Giyuu had stayed silent, allowing the boy with the scarred forehead say his peace; ready to correct him when—the girl lying beneath the boy caught his eyes.

Long black hair with orange tips and a bamboo muzzle blocking her mouth. She looked just the same as when Giyuu last saw them.

The demon girl and the human brother he had spared.

Giyuu stayed quiet during the _hashira_ evaluation of a corps member carrying a demon sister. At any other circumstances, Giyuu would have also rejected the idea of allowing a demon to live. But he was the one that allowed it. For, they had not seen what he had on that winter day two years ago. These siblings were different and the sister even more so. He had placed his hopes on them for a reason.

But he would not baby them. Tanjirou would have to fight harder, would defend harder against the criticism. Harboring a demon was against corps rules and despite how pitiful the siblings were; a demon was still a demon. Sanemi was bent on proving that true.

Giyuu's only help was taking Iguro's hand off Tanjirou's back before his body fails him. The boy had rushed to call out his sister's name, the demon salivating behind the bamboo muzzle at the sight of Sanemi's dripping blood. She was hungry, the wounds inflicted by Sanemi were taunting. Sweat gathered on her forehead from her restraint and silently, Giyuu watched with narrowed cold eyes for her next move.

He placed his trust in her; don't fail him now.

As if his silent prayer was heard, Nezuko looked away with a blatant refusal for the blood and ended the argument.

The _hashiras_ would not accept them even with Oyakata-sama's approval but that was none of Giyuu's concern. That was proof enough that the demon would not eat any humans. Tanjirou would be there to make sure of it.

And, if Giyuu was required, he would be there, too.

* * *

The Butterfly Estate was never a rambunctious place. The employees there, mostly young girls, were quiet and took care of the house when Shinobu was out on missions. Many demon slayers would pass by it at one point in their career as the estate would welcome them with open arms, healing and nursing the slayers back to health before their next mission.

Lately, Giyuu had been assigned to missions with Shinobu so his presence within the estate was not out of the norm. The young girls had learned to not disturb him; not because he was cruel but rather, he was unresponsive most often than not. He would come to retrieve the Insect Pillar or would stay a night for rest before heading out again.

But this time, as he entered the estate without Shinobu's presence within, he had not realized his original purpose was not for a mission. There were loud voices filling the backyard and echoing out the walls, voices Giyuu barely recognized until one.

"Nezuko was known as our town beauty!"

"OHHH! Yes, yes! She still is! Nezuko-chan is the cutest!"

"What is considered 'cute'?! How will that help you in battle?!"

Giyuu's steps stilled, the pointless conversation reaching his ears as he looked around the corner. The three boys were sitting on the ledge, Tanjirou in the middle while Zenitsu and Inosuke were arguing about beauty and power. They were resting well, Giyuu concluded, and he decided to not announce his appearance as he left to his next mission.

That was when he began to learn more about her; the only demon he had ever let live.

The information was always fleeting; a casual remark here, a deep discussion there. It was always unintentional. Giyuu had never intended to learn about the siblings personal lives. He had his own agenda to fulfill, his own personal demons to fight. Vouching for them was already the extent of his abilities.

And yet, he would return, sometimes accidental, other times as mindless wander. There were a few more times he had heard Tanjirou's discussion about his sister. Sometimes it was with the three orphaned girls Shinobu kept around. Sometimes, it was by himself. And somehow, Giyuu would remember them.

"Nezuko is named after okaa-san's favorite flower: the snowbell."

"Nezuko is good at hemming clothes, as well. I think she would love to learn your technique, Sumi-san. She…was always repairing her own clothes, never asking for new ones."

"Sleep well, Nezuko… You never had the chance to sleep much before, had you? Don't worry. Your big brother will be here to watch over you now."

"I will turn you back into a human, Nezuko. I promise."

Giyuu had heard those during the weeks of Tanjirou's recovery. He never made his presence known, only silently watching over the boy training and healing before setting off to somewhere unknown. He never once saw the demon in question, hearing more about her than actually ever seeing her.

The Kamado siblings care for each other. They were the only ones left. Tanjirou's strict protection for his sister was proof of his devotion and determination to turn her back into a human. She became a well known name within the Demon Slaying Corps but she seldom revealed her face. The two had easily won the Butterfly Estate over. Tanjirou, with his never-ending kindness and power. Nezuko, with her adorable childish features and quiet nature.

They reminded him of the ones Giyuu had lost. There was a resemblance of the siblings to his own family, of a sister he lost because she had protected him.

Giyuu was so weak.

Never again would he be able to see Tsutako-nee smile again. Never again would Tsutako-nee cook for him again. The dear sister he had lost; he will wear her _haori_ as a reminder to never part again.

But she was not the only one he had lost. There were countless others after her. Many were unfamiliar faces and the one to haunt him most often was a boy of stormy eyes and sunset hair.

Sabito should have been the one here, not him. Sabito should have been the Water Pillar, not him. Sabito should be _alive_, not him. He, who had saved everyone during their final selection, perished before Giyuu could even say goodbye. He was selfless and righteousness all mold into one, a slayer who would have been an honorable pillar if he had lived.

But Giyuu lost him, just like how he had lost the others.

So he mended his _haori_ again, this time the left side with the green and yellow pattern of him.

He would like to believe—if Sabito had been here, he would approve of what Giyuu had done. Letting a demon live for the sliver of chance to ending the demon race. The siblings were unique, Giyuu reiterated again, for Muzan had his eyes on them and wished to get rid of them. Killing Muzan was the only way to eradicate all demons.

It would be the only way for the dead to find peace.

* * *

"Nezuko likes head pats. It's really cute. Before, she would act so mature like kaa-san and hates it when I dote on her. She said I should pay attention to our younger siblings instead but...doesn't she know she's also my younger sister?"

Tanjirou was talking about her again. This time, Shinobu was seated quietly next to him as both were on top of the roof bathing in the moonlight. Giyuu did not intend to stop in, his journey would be passing by this path, but his steps slowed involuntarily and he had no choice but to listen.

"Now...she should be fourteen now and yet, she does not look older than twelve. She would shrink, too, and that makes her look like our youngest sibling, Rokuta. It makes me wonder...if she is staying a child for a reason. If she had not experienced childhood like our younger siblings and is now acting upon it…"

This conversation felt too personal and there was the odd twist of guilt in his stomach to overhear it.

"Then, you should spoil Nezuko-chan now, Tanjirou-san. Not many would have a second chance, like you."

That's right. Shinobu's elder sister, a former pillar, had died by the hands of a demon. In fact, all of them had related in that way. Giyuu was no stranger to loss, to incompetence.

A flash of blue eyes passed by his mind, the image of his smiling sister gone as fast as it appeared. Giyuu clenched his fists and disappeared, heading off to his next mission.

* * *

Rengoku Kyojuro's death was a startling blow to the Demon Slaying Corps.

One of the most notable pillars, an honorable man only one year his junior, had passed away due to one of the Twelve Demon Moons. The shock of his death shook the _hashira_'s foundation, stunning Giyuu when the crow announced his last words yet the only thing Giyuu could reply with was: I see.

Death surrounded them in a thinly placed veil. It was a relieving old friend when it comes to taking the demons away yet it was just as an astounding foe when it came to their loved ones. Death does not show favoritism. It only knew how to take, and take, and take.

When Giyuu entered the Butterfly Estate next, a somber air hung within the walls and lingered in the air. It was not the same rambunctious place he had seen before. Even when the girls were cleaning up the estate and was preparing to turn in for the night, it was only Aoi who greeted him quietly to see if he needed assistance—which he never did. Aoi did not question his return, merely stating that Shinobu-sama has yet to return and he was welcomed to stay in the guest room.

He wandered the halls, an unknown destination only his feet knew where to take him, but he stopped at a lone figure in his path. The moonlight shone down on her pale features, making her skin lighter in the darkness and the orange tint of her hair brighter. The same bamboo muzzle still constricted her mouth and when she turned to look in his direction, Giyuu saw the glowing pink eyes.

This was the fourth time he had seen the demon, the appearance unchanging as her brother had said. Giyuu recalled the conversation from however long ago, about how she was staying as a child for a reason unknown. She did look younger than the first he had seen her, but maybe that was because he only known her as the wild demon that fought to protect. This was the first time Giyuu had seen her when she was not feral or asleep.

She was calm. A blank expression on her face as the muzzle covered the lower part yet her eyes were solemnly looking in his direction. Her personality and cause for her current state was still unidentified; she only reacted around her brother. Whether she was actually aware of what was going on around her was unknown. This demon looked…perpetually sleepy.

But, she was not attacking him, like Tanjirou had adamantly proclaimed. This demon, his sister, the one and only demon Giyuu allowed to live, does not attack humans. As she lived amongst the estate with other humans, she spent the majority time in her box or asleep.

"What happened?" His voice was quiet in the night, a low question that wished to seek the truth of the Flame Pillar's passing.

Nezuko continued to look at him with those fathomless eyes but her eyebrows furrowed lightly and her head turned to the side, looking past the window where three young boys were passed out. She did not talk, though Giyuu was unsure she knew how. Even when he first met them, the demon could only snarl and growl.

Well, it mattered not. Giyuu knew how Rengoku had fought till the death even after spending the night protecting the humans within the train. It was only a curse for a Twelve Demon Moon to surprise them at the last minute, right when all were exhausted and worn from the night of the fight. But, of course, Rengoku would be the one to hold his ground. Rengoku would be the one to defend them with his life on the line.

And now, Rengoku Kyojuro was gone.

Another one too kind, too strong, too undeserving of death…was gone.

Something landed on his head, small fingers gliding over the black hair and smoothing down the unruly locks. Giyuu returned to the present, deep blue eyes meeting glowing pink as the demon lightly rubbed his head.

"_Nezuko likes head pats."_

Afterwards, when Giyuu recalled his meeting with the girl, he realized there were more emotions hidden behind those demonic eyes than he thought. There was sadness, longing, and an understanding with a quiet acceptance that unnerved his very heart, not realizing that his heart had sped up until he fled from the estate.

And, it wasn't until afterwards, after he was long gone from the Butterfly Estate, did he wonder if he looked as sad as he felt inside, for her to show him…comfort.

"_I accept Nezuko as a member of the Demon Hunters."_

Rengoku had made sure his words would pass on to through the crows.

Days past, feelings recovered, and the three boys were training with new vigor. Rengoku Kyojuro's death had left a scar in their hearts and an empty space within the pillars. Work intensified as their power dwindled and Giyuu took upon more missions to rid of the bloodthirsty demons.

Always unintentional, he would pass by the Butterfly Estate on his way out to another mission. It was an annoyingly placed thing, Giyuu found himself thinking once, because he happened to linger just a moment longer if those siblings were there.

Tanjirou had continued to train hard with an unwilling Zenitsu and the beastly Inosuke. Their shouts were often heard beyond the walls and the quieter, girly voices would sometimes follow.

It was never the demon's voice, Giyuu noticed, before quickly shoving those thoughts away and ignored the ghostly feel of pressure over his head.

So, it was a marvel when Tomioka Giyuu had appeared in the Butterfly Estate one night in front of Kamado Tanjirou, two wooden swords in hand before tossing one to the stunned boy.

"Your form needs refinement," Giyuu only said that much, shifting his feet on the ground and raised the sword. "Come."

The night was spent with him beating down Tanjirou. Not much was exchanged between them besides the quiet criticism from Giyuu. A part of him did not understand why he was doing this; Tanjirou's body was not suited to master the Breath of Water. But the training session did not long, maybe less than an hour, and both were called away to another mission.

Before he left, this time, Giyuu saw the demon girl sitting quietly by the side to watch them train. Her slitted pink eyes regarded him for a few seconds before returning her gaze back to the worn down boy on the ground. She got up on her short legs, ran over to crouch by Tanjirou, and stroked his head in comfort. Tanjirou's laugh filled the yard and Nezuko's eyes crinkled up into a smile.

Something odd twisted in his stomach and Giyuu left before he could decipher what it was.

* * *

The fall of an Upper Moon Six demon was a victory for the Demon Slaying Corps. But, what followed the demons defeat was the retirement on Uzui Tengen.

The news had shaken the Demon Slaying Corps yet Oyakata-sama had allowed his retirement without an argument. And, as Giyuu listened to the report by the _Kasugai_ crow, he realized the Kamado siblings were in the center of it all again.

As expected, their appearance had shifted something within their world of humanity. The Upper Moon Demons who had held their titles for centuries had finally fallen; even if it was only one, it sparked hope for the _hashiras_ for the future. There were two lost pillars now from the original nine; their power continued to dwindle but, Tengen was indifferent.

"_The young ones are flamboyantly improving! I am not worried so let me retire in peace!"_

Those words were just like Tengen, brash and careless yet fitting for the man of his caliber. Although he spoke of retirement, the Sound Pillar returned after a week of rest to continue his help for the corps. Maybe Oyakata-sama had seen that coming and allowed his retirement in the first place.

This time, when he returned to the Butterfly Estate, all three boys and the demon girl were recovering and asleep. All of them sustained different injuries, Inosuke's nearly life-threatening, but with meticulous care by the girls, the three were finally out of the danger zone.

He stopped by the window, the same spot Giyuu had previously stopped at before with the demon girl, and peered into the room. The three were lined up neatly on the hospital bed, fast asleep from the strenuous fight against the Upper Moon Demons. There was the wooden box Tanjirou always carried in the corner and Giyuu was about to leave—until he heard a small scratch within.

Deep blue eyes observed the small door of the box open, an equally small figure tumbling out and fumbling with the clothes too big for her size. Nezuko rubbed her vibrant pink eyes from sleep and looked up, first past the comatose boys, then to the stunned _hashira_ outside the window. Her body enlarged, growing in size from the small child to her regular form.

Still younger than her actual age, Giyuu recalled.

With careful steps, Nezuko walked towards the window. Her glowing pink eyes never leaving his form, sleepiness still clouding over her blank gaze but, if he looked closely, it nearly looked…crinkling upwards.

She stopped right before him, neck cranked up to look up at him. Nezuko did not move after and Giyuu stayed frozen, not sure why she had appeared in the first place. She seemed to huff behind the muzzle by the growing silence, tilting her head, and raised it up again in a subtle nod.

"_Nezuko likes head pats."_

Was…that what she wanted?

Giyuu was stunned again. Does she not remember how he was the one who stabbed her before? Why was she treating him as everyone else? Does she not fear him?

'_I have been influencing Nezuko to treat all humans like family. Humans are to be protected.'_

Urokodaki's letter had mentioned this. Giyuu should not be surprised; this demon had been protecting Tanjirou from the beginning and had been restraining herself from attacking humans. It was only surprising that she would approach him.

But, what was he supposed to do now?

He could leave. Giyuu was not meant to be here. His duty of killing demons was never-ending; this trip to the estate was always a small detour. If he turned his back now, no one would know he was here.

Nezuko's sudden step forward caught his attention, leaning forward at the open window and Giyuu reflexively raised his hand to block her forehead. She had stopped moving and he nearly froze from the contact. He watched with startled blue eyes at how she relaxed beneath him, adjusting her head so his palm rested on the top of her hair, and pink eyes closed in contentment.

From the warmth he felt on her head, to the relaxed and…happiness radiating from the girl, Giyuu found himself comparing her to a purring cat. Or, maybe a dog was more fitting for the way she looked so satisfied right now. The silent message she could not speak of; it felt as if she wanted to be praised for her hard work of keeping the boys safe.

Giyuu let go not even two seconds later. By the time Nezuko realized it, the _hashira_ had already disappeared beyond the window, leaving her to tilt her head in confusion.

* * *

Two months. Giyuu did not return for two months. He kept himself occupied with the demons, which was not difficult to do, and went to missions specifically on the other side of the land. And yet, he was still called upon return and passed by the Butterfly Estate once more.

"Nezuko cried again."

Tanjirou's voice, now awake, was soft in the room painted by the setting sun. As always, Giyuu's steps stilled again as he stayed hidden in the corner, hearing about something he should not know about a girl he never met as a human.

"Since her…transformation into a demon, I've only seen her cry once… That was in the beginning as she turned, trying to reach for me and—I had never felt so scared for my life. Not for me but—for my _imouto_."

Giyuu was uncertain of who Tanjirou may be speaking to. He kept his voice low and somber as if telling someone a secret.

"During the fight against the Upper Moon…Nezuko changed. In my unconscious state, I saw Takeo again…telling me to save Nezuko—because he was worried she might lose something precious one day. I could see it; I could understand what he meant. When I came to, the scent of her blood was overwhelming. She must have suffered a lot when I was just sleeping away. Nezuko—she changed into something more—demonic. It scared me. She wasn't listening to me—she was trying to attack humans and—I was so scared to lose her—! If…if it wasn't for Uzui-san…if it wasn't for okaa-san…I wouldn't have been able to calm her."

A silence passed by then, no sound coming from the room or the estate around them after the boy's tentative confession. He had done what he could to suppress Nezuko and succeeded in the end. Nezuko was the one most important to him now. It was not the risk of losing his life driving Tanjirou to fight her. It was because he loved her and feared losing her in the end.

"Otou-san, okaa-san, Takeo, Hanako, Shigeru, Rokuta…continue to watch over me. I swear I will turn Nezuko back into a human. I won't let her be hurt ever again."

Giyuu turned around with those last words. He had unintentionally trespassed onto another conversation. He needed to stop coming here—this habit of his was unbecoming.

"Oh my, Tomioka-san. I didn't expect to run into you so soon."

And, the last person he wanted to see was right in his path.

Shinobu kept the pleasant smile on her lips as she gestured down the wooden hall.

"Would you care to join me for a small walk?"

"I'm busy," Giyuu stated simply; he needed to return to his mission.

"Busy and yet still visited my estate without notice? How many times has it been now? Three?"

Giyuu felt his eye twitch. The teasing smile on the Insect Pillar's rosy lips were obvious. She was not oblivious to his random appearances at her home and his only little saving grace was that she only suspected _three_ visits total.

"It won't happen again."

"Now, now, that's not what I meant," Shinobu smiled wider, her theory on the stoic boy proven true when he did not deny her claims. She walked in step with him as he made his way towards the exit, her curiosity and amusement growing by his quick steps. "You sure know how to keep a girl guessing. At first, I thought you were only here to steal my snacks but apparently, Tanjirou-san had told me some interesting tidbits."

Giyuu did not answer but that did not deter the woman from continuing. Sometimes, he felt as if she only spoke with him to annoy him.

"Are you planning to take Tanjirou-san as your _Tsuguko_?" Shinobu wondered out loud, "You two do share the same Breath and you've actually trained him once! That's the closest I've seen you get close to anyone, Tomioka-san!"

Ah, so she did not know his true purpose. He stilled; what was his true purpose, exactly?

"No," he answered simply, "There is nothing else I need to train him on. He could become the next Water Pillar now."

That was not his position in the first place. The sooner Tanjirou becomes stronger, the sooner Giyuu could step down from this role he was never meant to receive. It belonged to Sabito; it belonged to Tanjirou. It belonged to someone stronger who did not cheat their way through the final selection.

"That's mean, Tomioka-san," Shinobu quietly laughed, "We are the pillars to guide the young ones to succession."

"I am not one of you."

"And you wonder why no one likes you."

Giyuu gave her a look, eyebrows pinched together and pursed lips as if refuting her statement. Shinobu continued to look at him with those teasing violet eyes and he refused to be baited again. He faced forward and leapt, disappearing from the estate before _she_ woke up.

* * *

They were summoned for another _hashira_ meeting to discuss their plans regarding the demon who conquered the sun.

Again, the clash of demons was revolved around the Kamado siblings and this time, Tanjirou nearly lost his sister. A more shocking discovery was the demon, the one and only from the past thousand years, was able to walk under the sun. Muzan would not let this opportunity go. He would do everything in his power to eat Nezuko and the pillars were preparing to face them.

Save, for Giyuu.

Tanjirou had defeated another Upper Moon Demon. He deserved to be the Water Pillar, not him. Giyuu was ready to resign his position to Oyakata-sama and he knew the leader must have known since the beginning that he never wanted to stay. But he continued to keep him there and Giyuu wanted nothing more than to leave.

As he wandered the streets, his feet led him to that familiar estate again. There were a bustling of noises from within under the scorching sun and, for a moment, he swore he heard a new voice.

_Aren't you curious?_ The voice whispered tauntingly in his mind.

Past the wooden doors with a butterfly emblem, past the shrub garden and stony path, past the recovery room he had found her before, Giyuu rounded the corner to see fluttering laundry. In the middle of the group of young girls, vibrant pink eyes turned to him first before the others even noticed his arrival.

It was real.

This demon was not disintegrating under the sun.

And she was walking towards him with lips pulled up into a smile to reveal her white fangs. She was still a demon but now, more human than ever. It was vastly different than her blank state from the past months, looking yet not seeing. Under the sun, Giyuu saw light in her eyes, an inkling of who she used to be, and before he knew it, Nezuko stopped right before him.

Just like that night.

Except this time, there was no wall or open window between them.

"Wel-come…back…Gi-yuu."

Her smile was blinding. Her pink eyes were nearly sparkling. She was looking at him full of hope and expectancy, long black hair slightly swaying from the wind and the orange tips brushed against his hand.

He reached up to her head, smoothing a stray lock down, and nearly felt Nezuko purr under his palm.

"_Nezuko was known as our town beauty!"_

Oh no.

This was bad.

Giyuu took his hand back, turned around, and left.

He should not be here. He could not keep coming back. He knew too much about this demon—girl—Nezu—

"You weren't here for Tanjirou-san."

A surprised gasp reached his ears, his form tensing even more as his cold blue eyes saw the lithe woman just by the gate. Giyuu clenched his fists and said nothing in reply, making way to walk past Shinobu.

"I did not intend for that to be a bad thing, Tomioka-san," Shinobu grasped his wrist, preventing his escape as he turned to glare at her. "Nezuko-chan knows more than you'd think. I'd like it if you can stop running away."

Quietly, Shinobu released his arm after and Giyuu disappeared.

He stopped by the nearby forest, one hand clutching the rough bark to stop his shivering.

_Don't tell me those things._

_I don't deserve it._

_I don't deserve to be happy._

* * *

He should have known Kamado Tanjirou would chase him down. He was a boy too kind for his own good, showing sympathies for demons even in their deaths. It only took one question from Tanjirou to relinquish the tightly locked memories of Sabito and Tsutako he had over them.

For so long, he wished he was the one dead and they were the ones to survive. For so long, he wished he could revert the time and redo everything with them.

But, that was only naïve thinking. Sabito had told him that, too. What a child he had been, acting like he was the only one suffering when all the pillars—all the demon slayers—had gone through what he had.

And so, Giyuu also accepted the pillar training.

It was time he stopped running away.

During Tanjirou's recovery, Giyuu had spent a day with him in appreciation for his help. They had a soba eating contest, which Tanjirou won, unsurprisingly. But afterwards, the boy continued to talk about the most mundane things. It felt like a first actual conversation Giyuu had in a long, long time.

And then, he began to talk about her.

"Nezuko would love these noodles," Tanjirou stared at the soup in the bowl, his voice filled with melancholy, "When she recovers, I'm going to take her out to eat so many yummy things!"

Giyuu did not know how to reply. Turning a demon back into a human was unheard of but Tanjirou had always said it with conviction. It was slowly becoming a reality; Nezuko was different from all the rest.

When they returned to the Butterfly Estate, Giyuu was relieved to know Shinobu was not there. Then, his eyes turned to the boy next to him—looking so happy and oblivious that Giyuu wondered if…he knew or not.

"Onii-chan."

Tanjirou immediately turned to the voice, his face lighting up with so much warmth and happiness to finally hear that phase from her voice again. Giyuu watched as the boy ran over to the smiling demon, both siblings reveling in each other's presence. Nezuko turned to him then, her face unchanging with her bright smile as she separated from Tanjirou to walk towards him.

"Gi-yuu."

"Oh, how odd," Tanjirou smiled in amusement, "I wonder when Nezuko learned your name."

He froze. He never remember telling it to her, either. The only time he spoke of his own name was during the very first time they met.

"Who knows," Giyuu tried not to read into it.

"Gi-yuu," Nezuko said again, with the same smile and a small head tilt, looking at him with those bright pink eyes and Giyuu knew what she wanted.

His hand reached up to pat her head, receiving a happy grin from her. Nezuko leaned closer; her head on his chest for comfort and Tanjirou went over to tug her away.

"Nezuko, you can't do that with everyone. Sorry—Kanroji-san, Shinobu-san, and everyone else have been spoiling her too much," Tanjirou apologized with a small smile.

His chest still felt warm, heart hammering from the brief contact and quickly waved it away. Nezuko did that with everyone. That was fine.

"I need to go prepare for my training."

"Ah, okay! See you next time, Giyuu-san!" Tanjirou still had the innocent appearance on.

Nezuko blinked but she kept the smile on her lips as she brought one hand up for a small wave.

"Bye-bye."

* * *

The next time he saw them, Tanjirou was saying goodbye to his sister. His training will soon begin now that he had recovered but due to Nezuko's special condition, she could not be left alone. Oyakata-sama had plans to keep Nezuko safe; Muzan's attack will come any day now. But the demon girl had to go into hiding and needed to be separated from her brother.

"It's okay, Nezuko. I will be back soon," Tanjirou did not want to leave either but they both had duties to fulfill. He rubbed her head soothingly just like an older brother would while Nezuko held onto the corner of his checkered sleeve.

"Onii-chan…"

"Now, now, don't worry," Tanjirou's smile seemed to strain; he was worried about her despite his own words. "Giyuu-san will escort you to someplace safe. After this is all over—after you are turned back into a human—we will never be separated again."

"Nezuko-san will be safe," Amane-sama had said in her normal, soothing tone. It reminded him of Oyakata-sama sometimes and Giyuu supposed as his wife, Amane-sama must also be a level-headed leader.

"Un, I know," Tanjirou said with a small, sad smile. "It's time to go."

He gave her one more pat on the head and Nezuko gently let go of his _haori_. For the first time since that winter day, they were forced to separate. Nezuko would have to be hidden somewhere and Tanjirou needed to get as strong as a pillar. The next fight against the demon would reveal the fate of them. Win, lose; death, survive. It all counted on them.

"He will be fine," Giyuu could only offer small words of comfort to the demon girl as they headed towards the hidden destination.

Nezuko's crestfallen face looked at him, then down again. Quietly, a hand reached out to grasp his, startling the boy into nearly freezing to look at the shorter girl.

"Be…fine," Nezuko repeated, her vocabulary consisted of repeating their words but somehow, he knew she understood what they meant.

"Yes," Giyuu said quietly, "And you will be safe."

"Safe," her hand squeezed his slightly and Giyuu felt her warmth spread towards him, "You will…be safe."

He did not know if she was merely parroting those words—or if she meant them.

* * *

The night of the battle happened too soon for them.

The remaining Upper Moon Demons were dangerous and Giyuu had to fight with all his power with Tanjirou just to defeat one. The battles were not over, Muzan has yet to be defeated, but at least—Nezuko was safe. At least, for this battle, Nezuko was not amongst them.

Oh, how he wished that to be true.

Oh, how Giyuu had wished Nezuko did not appear before them against Muzan, the pink in her eyes still demonic and the leaf patterned tattoos revealed her state. She was still not human—and she had appeared to help them.

"Nezuko—run!" Tanjirou screamed with all his might—because Nezuko cannot be here—Nezuko was at risk—because Muzan wanted her—wanted the Chosen Demon—please—just not Nezuko!

"I will—keep you safe," her voice was mature, her words clear and not parroted like before.

"Nezuko—no—please—! Don't!"

Giyuu tightened his grip on his sword yet Tanjirou's desperate pleas shook him, reflecting what he could not say out loud.

_Not her, too._

_You should run._

_Don't stay here._

_Please._

.

.

.

Muzan was defeated.

The rising sun from the horizon appeared as the demon who started it all—began to disintegrate. His hand, that demonic hand of the thousand-year old demon, pierced through Nezuko's chest as if in a sick, twisted joke to take her with him.

But—Nezuko can heal.

Nezuko will be fine.

Nezuko will liv—

"You are a demon, too," Muzan's last, raged words echoed through the battlefield, soon followed by craze laughter as he twisted his hand—causing the girl to scream out in agony. "You will also die—!"

"Shut up!"

Tanjirou cut through the hand Muzan had over her and brought Nezuko back to their side. As the last of the demon disappeared, they could still hear the wild laughter echoing around them.

But none of them were paying attention as Tanjirou held Nezuko in his arms, watching the hole in her chest with tear-filled eyes because it was not recovering—she was not healing—why won't she heal?!

"Nezuko! Hang in there—Nezuko! Heal—go to sleep—just—please!"

"Onii-chan," Nezuko only smiled. "It's okay."

"No, no, no, no—it's not! You'll be human—Tamayo-san's medicine will work—you just—need some time—!"

"It's okay," Nezuko continued to say.

The wounds from her legs began to burn and dissolve, same as any demons would when faced with the sun but—Muzan, the originator of all demons, had perished.

Now, his children would perish with him.

"No—don't—"

"Nezuko-chan!" Zenitsu cried.

"Dammit, Nebuko! You're not allowed to die! My underlings cannot die!" Even Inosuke was distressed.

Giyuu watched with frozen stillness as the others began to cry for her. He stood with nothing to say, nothing to do. Another was being taken right before his eyes. Even though Muzan was defeated, even though that should be the end of all sufferings—_she_ was going to leave him, too.

"Thank you, onii-chan. Thank you, Zenitsu-san. Thank you, Inosuke-san," Nezuko smiled brightly.

Her legs were gone now. The edge of her waist began to disappear and the other three momentarily stopped crying only to listen to her. She remembered their names—even during her demonic state, she remembered.

"I'm leaving ahead now," Nezuko continued to smile yet the corner of her eyes were wet.

Seeing all three of them crowd her, crying over her—made the bystanders tear up even more. Kanao fell on her knees, Kanroji was clutching onto Iguro to stifle her sobs, and many others were silently crying.

Giyuu could do nothing but watch.

Another too young, another too kind. She was being taken from him, too.

"Giyuu-san."

His eyes widened, vibrant pink eyes returned his gaze in an upward arc. The demon he let live those many years ago. The demon he spared. The girl he began to visit—to learn more about—the one who conquered the sun. The one who saved their lives.

"Thank you for giving me a chance."

Giyuu thought his heart stopped. He stepped forward, his knees touched the ground and his hand reached out.

"Nezuko—"

She faded before he could say any more.

The last they saw of her was Nezuko's bright smile.

* * *

Time continued to pass whether they liked it or not. Since Muzan's defeat, the Demon Slaying Corps had disbanded. Many lives were lost that night, adding onto the heartbreak of the ones that were lucky enough to survive.

Giyuu stood by the wooden cross tomb they made in her honor. Her body could not be recovered so they buried the wooden box Tanjirou always carried. The boy was barely recovering. His goal was tarnished. What he had worked so hard for disappeared right before his eyes. The defeat of Muzan meant the end of the demon race but in order to do so, he had sacrificed Nezuko for it.

"_It was what she wanted,"_ Tanjirou had said soullessly.

It was what she wanted; it was the right thing to do. All of them knew that but it still does not stop the heartache.

"Did you know you were going to die?"

The whistling of the wind answered him.

Those last words. Her last smile. Giyuu could not forget.

Another one added onto those he could not save.

But it was what she wanted.

It was the only way.

"You cared for her, too, didn't you?"

Tanjirou, wrapped in bandages just like him, approached Giyuu with soft steps. He did not look as depressed as when Nezuko passed. He was just worn, tired, oh so tired and alone.

Giyuu did not know how to reply. A lot of his passing had been accidental. Or, maybe it really wasn't accidental because he always found a way to her. His view of her changed, his feelings regarding her changed. He did not know when he began to see her more of a 'girl' than 'demon'.

"Shinobu-san asked me once, who I'd like to see Nezuko with once she turned back into human. At that time, I thought she was only teasing me because as an older brother, I would not want my precious sister to be married off so soon."

This was the most Tanjirou had spoken since that night. The boy was still so hurt, so tired, and Giyuu understood it all. He had to go through losing his family again. He could not accomplish the first half of his goal.

And now she was gone.

Gone like them all.

"It was the day we had the soba-eating contest. Did you know? At that time, she had glanced at you."

Giyuu tensed, turning towards the boy with vibrant burgundy eyes regarding him with a look of understanding, of sadness, of so many emotions in just a simple gaze. He turned back to the makeshift tomb, trying to imagine the girl and how she looked at her last moment.

Mature and beautiful.

Happiness and sorrow all in one.

Looking at him.

"Would…you have approved?" Giyuu whispered, unable to look Tanjirou in the eyes—unable to look at the brother of the one he should not have feelings for.

"It doesn't matter what I think as long as Nezuko is happy," Tanjirou smiled, "But eventually, I would. As long as they love her more than I do."

Again, Giyuu was at a loss of words.

Love. He doesn't believe his feelings ran deep. He was curious before. He placed hope on both of them. He may have learned more about her than he should and—was remembering every little thing.

But it was hopeless in the end.

They were speaking about the girl without a future. The one gone and lost.

"Well, it's all wishful thinking now," Tanjirou's voice shook and Giyuu could hear he was on the verge of tears. "Here, you should take this."

A small, pink ribbon was handed to him. Giyuu froze, recognizing that as one of the ribbons she always wore on her hair.

"No, I shouldn't," but Giyuu refused. In the end, he did not know her as well as the others. He was only a passing stranger to her.

"It's fine," Tanjirou insisted, "We all have one. Luckily, she wore plenty in her hair."

He gave a strained laugh, it was soft and it hurt his lungs but Tanjirou still smiled through. Unable to refuse anymore, Giyuu took the small ribbon into his hand, gently holding it as if holding onto her hand.

"I wish you happiness, Giyuu-san. Until we meet again."

* * *

Tanjirou rarely saw Giyuu after that. It had been a shock knowing his little sister had harbored some feelings for the Water Pillar. Now, with the threat of demons gone, Tanjirou spent his day idly by with Zenitsu and Inosuke, taking odd jobs and living in the Butterfly Estate with Kanao.

Sometimes, as he traveled to another for work, he thought he saw someone with long black hair bound by pink ribbon.

But he knew he was imagining things. Nezuko was gone now, gave her life for them, and all her ribbons were given out to those she loved.

Zenitsu carried his on his wrist, never once taking it off. If he was ever required to do strenuous chores or was in danger of dirtying it, he would harshly refuse to do anything until another cloth was wrapped around his wrist. Sometimes, Tanjirou can hear him talking to it in the deep of the night.

Inosuke hid his ribbon. Tanjirou thought he had lost it once but Inosuke harshly yelled at him for even getting the idea of him losing something. No, it was not lost. Once, when the boar head was taken off to eat, they saw the pink ribbon tied to a small strand of his midnight hair.

Tanjirou mended his earrings with the ribbon. Kanao had helped him attached the fabric onto the placard and the ribbon elongated the earring. It dangled on his ear and hovered over his shoulders as he moved but now, it was a part of him just as much as Zenitsu and Inosuke's.

And, sometimes, when the traveling swordsman came to visit them, Tanjirou smiled at the pink ribbon wrapped around the hilt of Giyuu's sword.

* * *

**A/N:**

God I had no idea why I wrote this fic but yeah this is another rareship of mine. Though the romance is a lot more subtle in this one. Accidentally references FF7 here.

IT'S BEEN SO LONG SINCE I'VE SEEN NEZUKO IN THE MANGA PLS I MISS HER QQ

Yes, I know this ship probably won't happen and is a super long shot but ehhh I love Giyuu and I love Nezuko. Though I do ship her with everyone and am happy to see Zenitsu/Nezuko be canon since that seems to be the direction it is going in. But more importantly, I just hope THEY WILL SURVIVE IN THE END. Although I wrote Nezuko dying—I really hope it won't come true but I ALSO WANT TO SEE HER FIGHT TOO AHHH

There's so much more in depth I wanna write for all the KnY characters but I wanted to focus more on Giyuu's POV. I wish there were more interactions and just Nezuko in general. They still haven't reached Muzan yet, we don't know where Nezuko is, AND I AM SO SAD FOR MUI-CHAN AND ALL THE PILLARS.

Okay, sorry for the rant! I hope you liked it! Reviews and comments would be much appreciated!


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